The aim of this study is to determine the influence of atmospheric circulation on the extreme cold days in Iran. The mean daily air temperature data from 663 weather stations in Iran during 21/03/1961 to 19/03/2004 are processed and interpolated through Kriging method for 18 * 18 Km pixels. A matrix is obtained as a result (15705 * 5214). Data of sea level pressure were collected from NCEP/NCAR, affiliates of National Centers for Environmental Prediction and The National Center for Atmospheric Research of the United States of America. In this study, an extreme cold temperature event is defined by Normalized Temperature Deviation (NTD) index. The data were ordered according to the magnitude and extremeness of cold events. First 500 coldest and the most pervasive days were selected as the sample by which the anomaly of sea level pressure was calculated. The coldest and the most pervasive cold occurrences in Iran are accompanying with four patterns of sea level pressure anomaly.